1. Field of the Invention
The present invention relates to systems and methods for peeling fresh commodities and, more particularly, to such systems and methods for peeling generally ellipsoidal fruits and vegetables, such as fresh citrus fruit and onions.
2. Description of Related Art
Consumer demand for fresh cut produce has stimulated a renewed interest in developing and improving automated fresh commodity peeling methods. Traditional techniques for citrus peeling, for example, typically have consisted of hand or mechanical peeling facilitated by steam treatment to loosen the peel and/or chemical digestion to remove peel remnants. However, since these techniques often damage the flesh, an enzymatic peeling process was developed to produce fruit more suitable for the fresh market (Bruemmer, U.S. Pat. No. 4,284,651; Kirk, U.S. Pat. No. 5,196,222; Elliott et al, U.S. Pat. No 5,200,217). This process of enzymatic peeling comprises scoring or perforating the fruit peel, submerging the fruit into solution containing an enzyme (pectinase and/or pectinase and cellulase), and forcing the solution into the peel with the use of a vacuum. Another method comprises using pressure pulses (Adams and Kirk, U.S. Pat. No. 5,000,967). The enzyme solution partially digests the pectin-rich albedo (the inner part of the peel) and the regions of the intersegment membranes and thus facilitates the separation of fruit from peel and sectioning of the fruit while leaving the flesh nearly intact.
Vacuum and pressure-pulse infusion are usually effective in imbuing the peel with solution. When the fruit surface is not sterilized and thoroughly cleaned, however, microbiological contaminants and chemical residues on the surface may desorb into solution while the fruit is submerged and contact the flesh during infusion. The likelihood of contamination increases if the infusion solution is reused in order to conserve water or enzyme.
Commercially available enzymatically peeled citrus fruit exhibit juice leakage and softening during storage in spite of apparent preservation of the integrity of segment membranes and juice vesicles. Although the quality of these fruit may be extended by low temperature and controlled-atmosphere storage and incorporation of chemicals such as calcium lactate, it was suspected that the observed loss of quality is caused in part by an inadvertent infusion of the enzyme(s) into the fruit and a subsequent catabolism of the flesh throughout the storage period.
A composition for washing and peeling citrus fruit has been disclosed by Askienazy et al. (U.S. Pat. No. 3,970,762). A device for peeling mandarin oranges has been disclosed in a Japanese patent issued to Yamato Seikan Co., Ltd. (Jap. Pat. No. 45-31354). Fruit peelers have also been disclosed by Polk (U.S. Pat. No. 2,277,003), Singer (U.S. Pat. No. 2,396,444), Vincent et al. (U.S. Pat. No. 3,700,017), Black (U.S. Pat. No. 4,446,782), Hatch (U.S. Pat. No. 4,729,299), Berube et al. (U.S. Pat. No. 4,738,195), Nagaoka (U.S. Pat. No. 4,998,466), le Grand et al. (U.S. Pat. No. 5,046,411), Foxcroft et al. (U.S. Pat. No. 5,105,734), Del Ser Gonzalez (U.S. Pat. No. 5,133,250), and Kirk (U.S. Pat. No. 5,231,921).
It is therefore an object of the present invention to provide a device, system, and method for peeling a fresh commodity.
It is an additional object to provide such an invention that does not introduce any foreign substances into the commodity to facilitate peeling.
It is a further object to provide such an invention useful for peeling citrus fruit.
It is another object to provide an invention that also produces a citrus peel having superior properties for use in food products.
It is yet an additional object to provide a device useful for peeling onions.
It is yet a further object to provide a commodity peeling system and method that is substantially fully automated.
Citrus fruit in general comprises an inner body comprising a plurality of radial adjacent fruit segments surrounded by a peel that consists of a flavedo (outer, colored peel portion) and an albedo (inner, white peel portion). Different varieties of citrus are more or less difficult to peel, and have more or less albedo, which should be removed for effective peeling. The device, system, and method presented herein address both of these problems by providing a system and method for preparing citrus fruit for peeling and a device and method for removing the peel. Although not intended to be limiting, the device, system, and method may be used on a variety of citrus fruit. In addition, the device and method may be used on other fresh commodities having a peel, particularly onions.
In U.S. Patent Nos. 5,560,951 and 5,817,360, which are commonly owned with the present application, and the disclosures of which are incorporated herein by reference, a method has been disclosed that comprises the steps of forming plural openings in the peel and infusing an aqueous solution between the cuticle and the fruit segments through the openings. A pressure differential is applied to the infusing water relative to the pressure exterior of the fruit sufficient to radially expand the peel and to separate the peel from the body of the fruit. The aqueous solution comprises water that is essentially free of any enzymes or other active ingredients in sufficient amounts to chemically attack or react with the cuticle, albedo, or fruit segments.
While this method has been found extremely effective as a pretreatment to facilitate peel removal, it is also desired to provide a device to peel the pretreated fruit and a system that will enable substantially complete automation of the process.
The system of the present invention, which broadly is for peeling a fresh commodity, comprises means for piercing a peel of the fresh commodity in a plurality of spaced-apart locations. Means for vacuum infusing the pierced commodity with an aqueous solution to loosen the peel are also provided, as well as means for making a plurality of scores in the infused commodity to a predetermined depth. Preferably, the scores are made along generally circumferential lines having substantially common endpoints.
Means for gripping the peel between the scores are next employed. The scoring and gripping means are engaged by a means for forcing the commodity into sequential communication therewith. The peel-gripping means is adapted to hold the peel to permit a release of a peeled commodity.
The peeling device in a particular embodiment comprises means for supporting the fresh commodity in a first position. The support means is movable between a position for retaining the commodity in the first position and a releasing position for permitting the commodity to leave the support means. The support means is biased to the retaining position.
Means are provided for impelling the commodity in a direction adapted to move the support means from the retaining position to the releasing position. Means are also provided for receiving the released commodity into a second position and for making a plurality of scores in the commodity to a predetermined depth with the commodity moving from the first to the second position. Preferably the scores are made along generally circumferential lines having substantially common endpoints.
Means are included for releasing the scored commodity from the second position and for receiving the scored commodity into a third position.
Means are provided for gripping the peel between the scores with the commodity moving from the second to the third position and for releasing the peeled commodity from the third position, such that the peel retained on the gripping means.
The features that characterize the invention, both as to organization and method of operation, together with further objects and advantages thereof, will be better understood from the following description used in conjunction with the accompanying drawing. It is to be expressly understood that the drawing is for the purpose of illustration and description and is not intended as a definition of the limits of the invention. These and other objects attained, and advantages offered, by the present invention will become more fully apparent as the description that now follows is read in conjunction with the accompanying drawing.